Businesses rely on a network of critical systems (e.g., computer and telephone systems) for everyday operation. Such systems are commonly utilized for storing and accessing information, communication, or manufacturing purposes. Most of these critical systems require a constant supply of direct current (DC) power to operate. Loss of power provided by a DC power supply to a critical system may result in failure of a business to be able to perform day to day operations.
A DC power supply receives a power input from an alternating current (AC) or DC power source, and provides a DC power output at a voltage required by the critical system. DC power supplies are designed to be capable of receiving power from multiple AC or DC sources in order to increase reliability by maintaining a constant supply of power. Such systems often require complex control or switching schemes in order to switch from one power source to another if one of the power sources is unavailable (e.g., due to a power failure). Often times the switching and control systems are very costly and/or very complex to operate.
One known DC power supply is capable of receiving multiple AC power inputs. The independent sources of power may have grounds which are not at the same potential, and as such, must be maintained in isolation from each other. The DC power supply includes a transformer for each separate AC power input, and control technology on both the primary and secondary side of each transformer. Complex isolation technology is provided on the secondary side of the transformer in order to maintain isolation of the separate power supply inputs. The duplication of technology on both the primary and secondary side of each transformer may result in a costly and complex DC power supply system.